// /*  
//  * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message  
//  * Digest Algorithm, as defined in RFC 1321.  
//  * Version 1.1 Copyright (C) Paul Johnston 1999 - 2002.  
//  * Code also contributed by Greg Holt  
//  * See http://pajhome.org.uk/site/legal.html for details.  
//  */

/*  
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally  
 * to work around bugs in some JS interpreters.  
 */
function safe_add(x, y) {
  var lsw = (x & 0xFFFF) + (y & 0xFFFF)
  var msw = (x >> 16) + (y >> 16) + (lsw >> 16)
  return (msw << 16) | (lsw & 0xFFFF)
}

/*  
 * Bitwise rotate a 32-bit number to the left.  
 */
function rol(num, cnt) {
  return (num << cnt) | (num >>> (32 - cnt))
}

/*  
 * These functions implement the four basic operations the algorithm uses.  
 */
function cmn(q, a, b, x, s, t) {
  return safe_add(rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b)
}
function ff(a, b, c, d, x, s, t) {
  return cmn((b & c) | ((~b) & d), a, b, x, s, t)
}
function gg(a, b, c, d, x, s, t) {
  return cmn((b & d) | (c & (~d)), a, b, x, s, t)
}
function hh(a, b, c, d, x, s, t) {
  return cmn(b ^ c ^ d, a, b, x, s, t)
}
function ii(a, b, c, d, x, s, t) {
  return cmn(c ^ (b | (~d)), a, b, x, s, t)
}

/*  
 * Calculate the MD5 of an array of little-endian words, producing an array  
 * of little-endian words.  
 */
function coreMD5(x) {
  var a = 1732584193
  var b = -271733879
  var c = -1732584194
  var d = 271733878

  for (var i = 0; i < x.length; i += 16) {
    var olda = a
    var oldb = b
    var oldc = c
    var oldd = d

    a = ff(a, b, c, d, x[i + 0], 7, -680876936)
    d = ff(d, a, b, c, x[i + 1], 12, -389564586)
    c = ff(c, d, a, b, x[i + 2], 17, 606105819)
    b = ff(b, c, d, a, x[i + 3], 22, -1044525330)
    a = ff(a, b, c, d, x[i + 4], 7, -176418897)
    d = ff(d, a, b, c, x[i + 5], 12, 1200080426)
    c = ff(c, d, a, b, x[i + 6], 17, -1473231341)
    b = ff(b, c, d, a, x[i + 7], 22, -45705983)
    a = ff(a, b, c, d, x[i + 8], 7, 1770035416)
    d = ff(d, a, b, c, x[i + 9], 12, -1958414417)
    c = ff(c, d, a, b, x[i + 10], 17, -42063)
    b = ff(b, c, d, a, x[i + 11], 22, -1990404162)
    a = ff(a, b, c, d, x[i + 12], 7, 1804603682)
    d = ff(d, a, b, c, x[i + 13], 12, -40341101)
    c = ff(c, d, a, b, x[i + 14], 17, -1502002290)
    b = ff(b, c, d, a, x[i + 15], 22, 1236535329)

    a = gg(a, b, c, d, x[i + 1], 5, -165796510)
    d = gg(d, a, b, c, x[i + 6], 9, -1069501632)
    c = gg(c, d, a, b, x[i + 11], 14, 643717713)
    b = gg(b, c, d, a, x[i + 0], 20, -373897302)
    a = gg(a, b, c, d, x[i + 5], 5, -701558691)
    d = gg(d, a, b, c, x[i + 10], 9, 38016083)
    c = gg(c, d, a, b, x[i + 15], 14, -660478335)
    b = gg(b, c, d, a, x[i + 4], 20, -405537848)
    a = gg(a, b, c, d, x[i + 9], 5, 568446438)
    d = gg(d, a, b, c, x[i + 14], 9, -1019803690)
    c = gg(c, d, a, b, x[i + 3], 14, -187363961)
    b = gg(b, c, d, a, x[i + 8], 20, 1163531501)
    a = gg(a, b, c, d, x[i + 13], 5, -1444681467)
    d = gg(d, a, b, c, x[i + 2], 9, -51403784)
    c = gg(c, d, a, b, x[i + 7], 14, 1735328473)
    b = gg(b, c, d, a, x[i + 12], 20, -1926607734)

    a = hh(a, b, c, d, x[i + 5], 4, -378558)
    d = hh(d, a, b, c, x[i + 8], 11, -2022574463)
    c = hh(c, d, a, b, x[i + 11], 16, 1839030562)
    b = hh(b, c, d, a, x[i + 14], 23, -35309556)
    a = hh(a, b, c, d, x[i + 1], 4, -1530992060)
    d = hh(d, a, b, c, x[i + 4], 11, 1272893353)
    c = hh(c, d, a, b, x[i + 7], 16, -155497632)
    b = hh(b, c, d, a, x[i + 10], 23, -1094730640)
    a = hh(a, b, c, d, x[i + 13], 4, 681279174)
    d = hh(d, a, b, c, x[i + 0], 11, -358537222)
    c = hh(c, d, a, b, x[i + 3], 16, -722521979)
    b = hh(b, c, d, a, x[i + 6], 23, 76029189)
    a = hh(a, b, c, d, x[i + 9], 4, -640364487)
    d = hh(d, a, b, c, x[i + 12], 11, -421815835)
    c = hh(c, d, a, b, x[i + 15], 16, 530742520)
    b = hh(b, c, d, a, x[i + 2], 23, -995338651)

    a = ii(a, b, c, d, x[i + 0], 6, -198630844)
    d = ii(d, a, b, c, x[i + 7], 10, 1126891415)
    c = ii(c, d, a, b, x[i + 14], 15, -1416354905)
    b = ii(b, c, d, a, x[i + 5], 21, -57434055)
    a = ii(a, b, c, d, x[i + 12], 6, 1700485571)
    d = ii(d, a, b, c, x[i + 3], 10, -1894986606)
    c = ii(c, d, a, b, x[i + 10], 15, -1051523)
    b = ii(b, c, d, a, x[i + 1], 21, -2054922799)
    a = ii(a, b, c, d, x[i + 8], 6, 1873313359)
    d = ii(d, a, b, c, x[i + 15], 10, -30611744)
    c = ii(c, d, a, b, x[i + 6], 15, -1560198380)
    b = ii(b, c, d, a, x[i + 13], 21, 1309151649)
    a = ii(a, b, c, d, x[i + 4], 6, -145523070)
    d = ii(d, a, b, c, x[i + 11], 10, -1120210379)
    c = ii(c, d, a, b, x[i + 2], 15, 718787259)
    b = ii(b, c, d, a, x[i + 9], 21, -343485551)

    a = safe_add(a, olda)
    b = safe_add(b, oldb)
    c = safe_add(c, oldc)
    d = safe_add(d, oldd)
  }
  return [a, b, c, d]
}

/*  
 * Convert an array of little-endian words to a hex string.  
 */
function binl2hex(binarray) {
  var hex_tab = "0123456789abcdef"
  var str = ""
  for (var i = 0; i < binarray.length * 4; i++) {
    str += hex_tab.charAt((binarray[i >> 2] >> ((i % 4) * 8 + 4)) & 0xF) +
      hex_tab.charAt((binarray[i >> 2] >> ((i % 4) * 8)) & 0xF)
  }
  return str
}

/*  
 * Convert an array of little-endian words to a base64 encoded string.  
 */
function binl2b64(binarray) {
  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
  var str = ""
  for (var i = 0; i < binarray.length * 32; i += 6) {
    str += tab.charAt(((binarray[i >> 5] << (i % 32)) & 0x3F) |
      ((binarray[i >> 5 + 1] >> (32 - i % 32)) & 0x3F))
  }
  return str
}

/*  
 * Convert an 8-bit character string to a sequence of 16-word blocks, stored  
 * as an array, and append appropriate padding for MD4/5 calculation.  
 * If any of the characters are >255, the high byte is silently ignored.  
 */
function str2binl(str) {
  var nblk = ((str.length + 8) >> 6) + 1 // number of 16-word blocks    
  var blks = new Array(nblk * 16)
  for (var i = 0; i < nblk * 16; i++) blks[i] = 0
  for (var i = 0; i < str.length; i++)
    blks[i >> 2] |= (str.charCodeAt(i) & 0xFF) << ((i % 4) * 8)
  blks[i >> 2] |= 0x80 << ((i % 4) * 8)
  blks[nblk * 16 - 2] = str.length * 8
  return blks
}

/*  
 * Convert a wide-character string to a sequence of 16-word blocks, stored as  
 * an array, and append appropriate padding for MD4/5 calculation.  
 */
function strw2binl(str) {
  var nblk = ((str.length + 4) >> 5) + 1 // number of 16-word blocks    
  var blks = new Array(nblk * 16)
  for (var i = 0; i < nblk * 16; i++) blks[i] = 0
  for (var i = 0; i < str.length; i++)
    blks[i >> 1] |= str.charCodeAt(i) << ((i % 2) * 16)
  blks[i >> 1] |= 0x80 << ((i % 2) * 16)
  blks[nblk * 16 - 2] = str.length * 16
  return blks
}

/*  
 * External interface  
 */
function hexMD5(str) { return binl2hex(coreMD5(str2binl(str))) }
function hexMD5w(str) { return binl2hex(coreMD5(strw2binl(str))) }
function b64MD5(str) { return binl2b64(coreMD5(str2binl(str))) }
function b64MD5w(str) { return binl2b64(coreMD5(strw2binl(str))) }
/* Backward compatibility */
function calcMD5(str) { return binl2hex(coreMD5(str2binl(str))) }
module.exports = {
  MD5: hexMD5
}  
// var rotateLeft = function (lValue, iShiftBits) {
//   return (lValue << iShiftBits) | (lValue >>> (32 - iShiftBits));
// }

// var addUnsigned = function (lX, lY) {
//   var lX4, lY4, lX8, lY8, lResult;
//   lX8 = (lX & 0x80000000);
//   lY8 = (lY & 0x80000000);
//   lX4 = (lX & 0x40000000);
//   lY4 = (lY & 0x40000000);
//   lResult = (lX & 0x3FFFFFFF) + (lY & 0x3FFFFFFF);
//   if (lX4 & lY4) return (lResult ^ 0x80000000 ^ lX8 ^ lY8);
//   if (lX4 | lY4) {
//     if (lResult & 0x40000000) return (lResult ^ 0xC0000000 ^ lX8 ^ lY8);
//     else return (lResult ^ 0x40000000 ^ lX8 ^ lY8);
//   } else {
//     return (lResult ^ lX8 ^ lY8);
//   }
// }

// var F = function (x, y, z) {
//   return (x & y) | ((~x) & z);
// }

// var G = function (x, y, z) {
//   return (x & z) | (y & (~z));
// }

// var H = function (x, y, z) {
//   return (x ^ y ^ z);
// }

// var I = function (x, y, z) {
//   return (y ^ (x | (~z)));
// }

// var FF = function (a, b, c, d, x, s, ac) {
//   a = addUnsigned(a, addUnsigned(addUnsigned(F(b, c, d), x), ac));
//   return addUnsigned(rotateLeft(a, s), b);
// };

// var GG = function (a, b, c, d, x, s, ac) {
//   a = addUnsigned(a, addUnsigned(addUnsigned(G(b, c, d), x), ac));
//   return addUnsigned(rotateLeft(a, s), b);
// };

// var HH = function (a, b, c, d, x, s, ac) {
//   a = addUnsigned(a, addUnsigned(addUnsigned(H(b, c, d), x), ac));
//   return addUnsigned(rotateLeft(a, s), b);
// };

// var II = function (a, b, c, d, x, s, ac) {
//   a = addUnsigned(a, addUnsigned(addUnsigned(I(b, c, d), x), ac));
//   return addUnsigned(rotateLeft(a, s), b);
// };

// var convertToWordArray = function (string) {
//   var lWordCount;
//   var lMessageLength = string.length;
//   var lNumberOfWordsTempOne = lMessageLength + 8;
//   var lNumberOfWordsTempTwo = (lNumberOfWordsTempOne - (lNumberOfWordsTempOne % 64)) / 64;
//   var lNumberOfWords = (lNumberOfWordsTempTwo + 1) * 16;
//   var lWordArray = Array(lNumberOfWords - 1);
//   var lBytePosition = 0;
//   var lByteCount = 0;
//   while (lByteCount < lMessageLength) {
//     lWordCount = (lByteCount - (lByteCount % 4)) / 4;
//     lBytePosition = (lByteCount % 4) * 8;
//     lWordArray[lWordCount] = (lWordArray[lWordCount] | (string.charCodeAt(lByteCount) << lBytePosition));
//     lByteCount++;
//   }
//   lWordCount = (lByteCount - (lByteCount % 4)) / 4;
//   lBytePosition = (lByteCount % 4) * 8;
//   lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80 << lBytePosition);
//   lWordArray[lNumberOfWords - 2] = lMessageLength << 3;
//   lWordArray[lNumberOfWords - 1] = lMessageLength >>> 29;
//   return lWordArray;
// };

// var wordToHex = function (lValue) {
//   var WordToHexValue = "",
//     WordToHexValueTemp = "",
//     lByte, lCount;
//   for (lCount = 0; lCount <= 3; lCount++) {
//     lByte = (lValue >>> (lCount * 8)) & 255;
//     WordToHexValueTemp = "0" + lByte.toString(16);
//     WordToHexValue = WordToHexValue + WordToHexValueTemp.substr(WordToHexValueTemp.length - 2, 2);
//   }
//   return WordToHexValue;
// };

// var uTF8Encode = function (string) {
//   string = string.replace(/\x0d\x0a/g, "\x0a");
//   var output = "";
//   for (var n = 0; n < string.length; n++) {
//     var c = string.charCodeAt(n);
//     if (c < 128) {
//       output += String.fromCharCode(c);
//     } else if ((c > 127) && (c < 2048)) {
//       output += String.fromCharCode((c >> 6) | 192);
//       output += String.fromCharCode((c & 63) | 128);
//     } else {
//       output += String.fromCharCode((c >> 12) | 224);
//       output += String.fromCharCode(((c >> 6) & 63) | 128);
//       output += String.fromCharCode((c & 63) | 128);
//     }
//   }
//   return output;
// };

// function md5(string) {
//   var x = Array();
//   var k, AA, BB, CC, DD, a, b, c, d;
//   var S11 = 7,
//     S12 = 12,
//     S13 = 17,
//     S14 = 22;
//   var S21 = 5,
//     S22 = 9,
//     S23 = 14,
//     S24 = 20;
//   var S31 = 4,
//     S32 = 11,
//     S33 = 16,
//     S34 = 23;
//   var S41 = 6,
//     S42 = 10,
//     S43 = 15,
//     S44 = 21;
//   string = uTF8Encode(string);
//   x = convertToWordArray(string);
//   a = 0x67452301;
//   b = 0xEFCDAB89;
//   c = 0x98BADCFE;
//   d = 0x10325476;
//   for (k = 0; k < x.length; k += 16) {
//     AA = a;
//     BB = b;
//     CC = c;
//     DD = d;
//     a = FF(a, b, c, d, x[k + 0], S11, 0xD76AA478);
//     d = FF(d, a, b, c, x[k + 1], S12, 0xE8C7B756);
//     c = FF(c, d, a, b, x[k + 2], S13, 0x242070DB);
//     b = FF(b, c, d, a, x[k + 3], S14, 0xC1BDCEEE);
//     a = FF(a, b, c, d, x[k + 4], S11, 0xF57C0FAF);
//     d = FF(d, a, b, c, x[k + 5], S12, 0x4787C62A);
//     c = FF(c, d, a, b, x[k + 6], S13, 0xA8304613);
//     b = FF(b, c, d, a, x[k + 7], S14, 0xFD469501);
//     a = FF(a, b, c, d, x[k + 8], S11, 0x698098D8);
//     d = FF(d, a, b, c, x[k + 9], S12, 0x8B44F7AF);
//     c = FF(c, d, a, b, x[k + 10], S13, 0xFFFF5BB1);
//     b = FF(b, c, d, a, x[k + 11], S14, 0x895CD7BE);
//     a = FF(a, b, c, d, x[k + 12], S11, 0x6B901122);
//     d = FF(d, a, b, c, x[k + 13], S12, 0xFD987193);
//     c = FF(c, d, a, b, x[k + 14], S13, 0xA679438E);
//     b = FF(b, c, d, a, x[k + 15], S14, 0x49B40821);
//     a = GG(a, b, c, d, x[k + 1], S21, 0xF61E2562);
//     d = GG(d, a, b, c, x[k + 6], S22, 0xC040B340);
//     c = GG(c, d, a, b, x[k + 11], S23, 0x265E5A51);
//     b = GG(b, c, d, a, x[k + 0], S24, 0xE9B6C7AA);
//     a = GG(a, b, c, d, x[k + 5], S21, 0xD62F105D);
//     d = GG(d, a, b, c, x[k + 10], S22, 0x2441453);
//     c = GG(c, d, a, b, x[k + 15], S23, 0xD8A1E681);
//     b = GG(b, c, d, a, x[k + 4], S24, 0xE7D3FBC8);
//     a = GG(a, b, c, d, x[k + 9], S21, 0x21E1CDE6);
//     d = GG(d, a, b, c, x[k + 14], S22, 0xC33707D6);
//     c = GG(c, d, a, b, x[k + 3], S23, 0xF4D50D87);
//     b = GG(b, c, d, a, x[k + 8], S24, 0x455A14ED);
//     a = GG(a, b, c, d, x[k + 13], S21, 0xA9E3E905);
//     d = GG(d, a, b, c, x[k + 2], S22, 0xFCEFA3F8);
//     c = GG(c, d, a, b, x[k + 7], S23, 0x676F02D9);
//     b = GG(b, c, d, a, x[k + 12], S24, 0x8D2A4C8A);
//     a = HH(a, b, c, d, x[k + 5], S31, 0xFFFA3942);
//     d = HH(d, a, b, c, x[k + 8], S32, 0x8771F681);
//     c = HH(c, d, a, b, x[k + 11], S33, 0x6D9D6122);
//     b = HH(b, c, d, a, x[k + 14], S34, 0xFDE5380C);
//     a = HH(a, b, c, d, x[k + 1], S31, 0xA4BEEA44);
//     d = HH(d, a, b, c, x[k + 4], S32, 0x4BDECFA9);
//     c = HH(c, d, a, b, x[k + 7], S33, 0xF6BB4B60);
//     b = HH(b, c, d, a, x[k + 10], S34, 0xBEBFBC70);
//     a = HH(a, b, c, d, x[k + 13], S31, 0x289B7EC6);
//     d = HH(d, a, b, c, x[k + 0], S32, 0xEAA127FA);
//     c = HH(c, d, a, b, x[k + 3], S33, 0xD4EF3085);
//     b = HH(b, c, d, a, x[k + 6], S34, 0x4881D05);
//     a = HH(a, b, c, d, x[k + 9], S31, 0xD9D4D039);
//     d = HH(d, a, b, c, x[k + 12], S32, 0xE6DB99E5);
//     c = HH(c, d, a, b, x[k + 15], S33, 0x1FA27CF8);
//     b = HH(b, c, d, a, x[k + 2], S34, 0xC4AC5665);
//     a = II(a, b, c, d, x[k + 0], S41, 0xF4292244);
//     d = II(d, a, b, c, x[k + 7], S42, 0x432AFF97);
//     c = II(c, d, a, b, x[k + 14], S43, 0xAB9423A7);
//     b = II(b, c, d, a, x[k + 5], S44, 0xFC93A039);
//     a = II(a, b, c, d, x[k + 12], S41, 0x655B59C3);
//     d = II(d, a, b, c, x[k + 3], S42, 0x8F0CCC92);
//     c = II(c, d, a, b, x[k + 10], S43, 0xFFEFF47D);
//     b = II(b, c, d, a, x[k + 1], S44, 0x85845DD1);
//     a = II(a, b, c, d, x[k + 8], S41, 0x6FA87E4F);
//     d = II(d, a, b, c, x[k + 15], S42, 0xFE2CE6E0);
//     c = II(c, d, a, b, x[k + 6], S43, 0xA3014314);
//     b = II(b, c, d, a, x[k + 13], S44, 0x4E0811A1);
//     a = II(a, b, c, d, x[k + 4], S41, 0xF7537E82);
//     d = II(d, a, b, c, x[k + 11], S42, 0xBD3AF235);
//     c = II(c, d, a, b, x[k + 2], S43, 0x2AD7D2BB);
//     b = II(b, c, d, a, x[k + 9], S44, 0xEB86D391);
//     a = addUnsigned(a, AA);
//     b = addUnsigned(b, BB);
//     c = addUnsigned(c, CC);
//     d = addUnsigned(d, DD);
//   }
//   var tempValue = wordToHex(a) + wordToHex(b) + wordToHex(c) + wordToHex(d);
//   return tempValue.toLowerCase();
// }

// module.exports.md5 = md5 